There has been a growing interest in recent years in Interstitial Lung Disease (I.L.D.), specifically pulmonary sarcoidosis, centering around the relationship of BAL data and the intensity on gallium lung images to quantitate the alveolitis of this disorder. The mechanism(s) of 67Ga-citrate uptake into the BAL cellular fraction in patients with I.L.D. has never been established. The mechanisms for tumor cell uptake for 67Ga-citrate are well established and include: 1. Uptake of free 67Ga-citrate through passive diffusion. 2. Uptake of free 67Ga-citrate in the presence of gallium binding proteins, transferrin or lactoferrin. 3. Uptake of 67Ga complexed to either transferrin or lactoferrin. The purposes of this project are: 1. To elucidate the mechanism of 67Ga-citrate accumulation into the cellular fraction of BAL in patients with interstitial lung disease (I.L.D.), specifically pulmonary sarcoidosis. Our project will parallel the investigational processes that recognized these mechanisms promoting 67Ga-citrate uptake into tumor cells. 2. To determine if there is a difference in 67Ga-citrate uptake in the normal lung vs. the diseased lung. This investigation will utilize the following procedures: basic biochemical techniques, macrophage tissue culture techniques, gel chromatography column technique, iodination of proteins, purification of protein, cellular extraction techniques, induction of antiserum (goat) and induction of granulomas (rabbits). The significance of this project are: 1. To establish a strong correlation between 67Ga scan and bronchoalveolar lavage data. 2. To improve the diagnostic sensitivity and specificity of 67Ga scanning.